BRAKES
SECTION 5
CONTENTS OF THIS SECTION
Duo Servo Brakes
Disc Brakes
Page
5-1 Power Brakes
5-24 Special Tools
Page
5-31
5-32
DUO-SERVO BRAKES
INDEX
Page
General Description 5-1
Maintenance and Adjustments 5-3
Hydraulic Brake Fluid .. . 5-3
Bleeding Hydraulic System 5-3
Pressure Bleeding 5-3
Manual Bleeding 5_4
Push Rod to Main Cylinder Clearance 5-5
Hydraulic Brake Lines 5-5
Hydraulic Brake Hose 5-5
Hydraulic Brake Tubing 5-6
Brake Adjustment. .................... 5-7
Service Brake 5-7
Parking Brake 5-8
Component Replacement and Repairs 5-9
Parking Brake - Chevrolet, Chevelle and
Camaro 5^9
Pedal Assembly 5-9
Front Cable ,. . . 5-9
Center Cable 5-9
Rear Cables. . 5-9
Parking Brake - Chevy n 5-9
Lever Assembly 5-9
Idler Lever 5-11
Front Cable 5-11
Rear Cable . . ; 5-12
Parking Brake - Corvette 5-13
Lever Assembly . . . . 5-13
Front Cable 5-14
Rear Cable . . 5-14
Brake Pedal 5-15
Shoes and Linings 5-16
Organic 5-16
Metallic 5-17
Main Cylinder 5-18
Wheel Cylinders 5-21
Anchor Pin 5-22
Front Wheel 5-22
Rear Wheel 5-22
Brake Drums • 5-22
Brake Pipe Distribution and Switch Assembly . . . . . 5-23
Camaro Pressure Regulator Valve 5-23
GENERAL DESCRIPTION
All 1967 models are equipped with a new split brake
system as a safety feature. If a wheel cylinder or brake
line should fail at either the front end or rear end of
the vehicle, the operator can still bring the vehicle to
a controlled stop. The system is designed with separate
hydraulic systems for the front and rear brake using
a dual master cylinder (fig. 1). The design of the master
cylinder is similar to that used on the 1966 Corvette
in that it has two entirely separate reservoirs and outlets
in a common body casting. The front reservoir and outlet
is connected to the front wheel brakes, and the rear
reservoir and outlet is connected to the rear wheel
brakes. Two pistons within the master cylinder receive
mechanical pressure from the brake pedal push rod and
transmit it through the brake lines as hydraulic pressure
to the wheel cylinders. The filler cap is accessible from
inside the engine compartment.
A new brake pipe distribution and switch assembly
is mounted below the main cylinder. The front and rear
hydraulic brake lines are routed from the main cylinder,
through the brake pipe distribution and switch assembly,
to the front and rear brakes as shown in Figure 2. The
switch is wired electrically to the brake alarm indicator
light on the instrument panel. In the event of fluid loss
in either the front or rear brake system the indicator
on the instrument panel will illuminate red. (The indi-
cator will also' be illuminated when the parking brake is
applied.)
On Camaro models equipped with air conditioning, the
rear brake hydraulic line is routed through a pressure
regulator valve mounted on the left frame side rail
(fig. 3). The valve controls the hydraulic pressure to
the rear brakes resulting in the correct pressure balance
between the front and rear hydraulic systems.
The self-adjusting brakes (fig. 4), used on both front
and rear of all models, are the Duo-Servo single anchor
type which utilize the momentum of the vehicle to assist
in the brake application. The self-energizing or
self-
actuating force is applied to both brake shoes at each
wheel in both forward and reverse motion. The brake
shoe linings are bonded to the shoes.
Wheel cylinders are the double piston type permitting
even distribution of pressure to each brake shoe. To
keep out dust and moisture, both ejads of each wheel
cylinder are sealed with a rubber booC The wheel
cylinders have no adjustments.
The Chevrolet, Chevelle, and Camaro parking brakes
have a foot operated ratchet type pedal mounted to the
left of the steering column. A cable assembly connects
the pedal to an intermediate cable by means of an equal-
izer, where the adjustment for the parking brake is
incorporated. The intermediate cable attaches to the
CHEVROLET CHASSIS SERVICE MANUAL
BRAKES
5-24
DISC BRAKES
INDEX
Page
General Description
. 5-24
Maintenance
and
Adjustments
5-24
Bleeding Hydraulic System
5-24
Parking Brake Adjustment
-
Corvette
5-24
Component Replacement
and
Repairs
5-25
Page
Brake Shoes
. . . . . 5-25
Brake Caliper
5-26
Brake Disc
5-29
Main Cylinder.
5-30
Parking Brake Shoes
-
Corvette
5-30
GENERAL DESCRIPTION
Four wheel disc brakes
are
standard equipment
on
the
1967
Corvette,
as in 1966. The
Corvette
may
also
be equipped with heavy duty disc brakes which include
new front calipers, shoes, linings,
and
rear pressure
regulator valve. This heavy duty option
is
used
in
conjunction with
a
vacuum power unit. Front wheel disc
brakes
are
installed
as
optional equipment
on
Chevrolet,
Chevelle, Camaro,
and
Chevy
II
models.
The disc brake,
(fig. 35),
consists
of a
fixed caliper,
rotating disc, splash shield,
and
mounting bracket.
The
caliper assembly contains four pistons and two shoe
and
lining assemblies with
the
lining riveted
to the
steel
shoes.
A
seal
and
dust boot
are
installed
on
each piston,
with
a
piston spring
in the
caliper cylinder bore beneath
each piston.
A
retaining pin extends through each caliper
half
and
both shoes
to
hold
the
shoes and linings
in
posi-
tion
in the
caliper.
On
Corvette heavy duty disc brakes,
two retaining cotter pins
are
used
at
each end
of the
caliper
to
secure
the
shoes
and
linings. Machined
sur-
faces within
the
caliper prevent
the
shoe
and
lining
assembly from rotating with
the
brake disc when pres-
sure
is
applied.
The disc, which
has a
series
of air
vent louvers
to
provide cooling,
is
mounted
on the
front wheel-hub.
The caliper straddles
the
disc and mounts
on a
mounting
bracket attached
to the
steering knuckle with
two
bolts.
The Corvette heavy duty option includes
a
pressure
regulator valve mounted
in the
rear brake line just
below
the
main cylinder. Chevrolet, Chevelle, Camaro,
and Chevy
n
models with disc brakes have
a
pressure
regulator valve mounted
in the
front brake line just
below
the
main cylinder. The valve controls
the
hydraulic
pressure
to the
front
or
rear brakes,
as
applicable,
resulting,
in the
correct pressure balance between
the
front
and
rear hydraulic systems. This valve guards
against premature .lock-up
of
front
or
rear wheels when
brakes
are
applied.
Maintenance, adjustment,
and
service operations which
are
not
included
in
this section
are the
same
as for
the Duo-Servo type brakes.
MAINTENANCE
AND
ADJUSTMENTS
BLEEDING HYDRAULIC SYSTEM
The operation
of
bleeding
the
disc brake hydraulic
system
is the
same
as for
Duo-Servo system outlined
in
the
front
of
this section. Note
the
exceptions below
and refer
to
bleeding procedures under Duo-Servo
brakes.
1.
When pressure bleeding equipment
is
used,
the
correct pressure setting
for
bleeding disc brakes
is 10-2.0
lbs. on
Corvette,
and 40 lbs. on all
other
models.
2.
The
front calipers contain
one
bleeder valve.
The
rear calipers
on
Corvette contain two bleeder valves
(one inboard
and one
outboard) which necessitates
the removal
of the
rear wheels
for
bleeding.
3.
Tapping
the
caliper with
a
rawhide mallet
as the
fluid
is
flowing
out may
assist
in
obtaining
a
good
bleeding
job.
4.
On
Chevrolet, Chevelle, Camaro
and
Chevy
II, the
spring loaded
end of the
pressure regulator valve
(fig.
36)
must
be
held (valve
in
open position) while
bleeding. This
is
done
by
depressing
and
holding
in
the
plunger
in the
end
of
the valve either
by
hand,
by taping,
or by
clamping.
PARKING BRAKE-CORVETTE
Adjustment
1.
Raise rear
end of
vehicle
and
place
on
jack stands.
2.
Remove rear wheels.
3/
Loosen brake cables
at the
equalizer until
the
park-
ing brake levers move freely
to the "off"
position
with slack
in the
cables.
4.
Turn
the
disc until
the
adjusting screw can
be
seen
through
the
hole
in the
disc.
5. Insert
an
adjusting tool
or
screw driver through
the
hole
in the
disc
and
tighten
the
adjusting screw
by
moving your hand away from
the
floor
on
both
the
left and right sides
(fig. 37).
6. Tighten until
the
disc will
not
move, then back
off
ten
(10)
notches.
7. Apply
the
parking brake four
(4)
notches from inside
the
car.
8. Tighten
the
brake cables
at the
equalizer
to
produce
a light drag with
the
wheels mounted.
9. Fully release
the
parking brake handle
and
rotate
the rear wheels.
No
drag should be evident with
the
handle released.
CHEVROLET CHASSIS SERVICE MANUAL
CLUTCH AND TRANSMISSIONS 7-36
TURBO HYDRA-MATIC TRANSMISSION
INDEX
Page
General Description . . , . 7-36
Maintenance and Adjustments . 7-37
Transmission Fluid 7-37
Fluid Level Indicator 7-37
Shift Control Linkage Adjustment ........... 7-37
Neutral Safety Switch Adjustment 7-37
Draining and Refilling Transmission . . . 7-37
Pressure Regulator Valve 7-38
Control Valve Body . 7-39
Governor ..'.... 7-40
Modulator and Modulator Valve 7-40
Parking Linkage . . 7-40
Page
Rear Seal -. 7-40
Other Service Operations . . 7-40
Transmission Replacement 7-40
Turbo Hydra-Matic Diagnosis Procedure. ......... 7-41
Sequence . ; ; 7-41
Oil Level and Condition Check 7-41
Manual Linkage 7-41
Oil Leaks .' 7-41
Case Porosity - Repair ................ 7-42
Oil Pressure Check 7-42
Transmission Shift Points 7-42
Special Tools 7-43
GENERAL DESCRIPTION
The Turbo Hydra-Matic transmission is a fully auto-
matic unit consisting primarily of a 3-element hydraulic
torque converter and a compound planetary gear set.
Three multiple-disc clutches, one sprag unit, one roller
clutch and two bands provide the friction elements re-
quired to obtain the desired function of the compound
planetary gear set.
The torque converter couples the engine to the plane-
tary gears through oil and provides hydraulic torque
multiplication when required. The compound planetary
gear set produces three forward speeds and reverse.
The
3-
element torque converter consists of a pump or
driving member, a turbine or driven member, and a
stator assembly. The stator is mounted on a one-way
roller clutch which will allow the stator to turn clock-
wise but not counter-clockwise.
The torque converter housing is filled with oil and
is attached to the engine crankshaft by a flex plate and
always rotates at engine speed. The converter pump is
an integral part of the converter housing, therefore the
pump blades, rotating at engine speed, set the oil within
the converter into motion and direct it to the turbine,
causing the turbine to rotate.
As the oil passes through the turbine it is traveling in
such a direction that if it were not re-directed by the
stator it would hit the rear of the converter pump blades
and impede its pumping action. So at low turbine speeds,
the oil is re-directed by the stator to the converter pump
in such a manner that it actually assists the converter
pump to deliver power or multiply engine torque.
As turbine speed increases, the direction of the oil
leaving the turbine changes and flows against the rear
side of the stator vanes in a clockwise direction. Since
the stator is now impeding the smooth flow of oil, its
roller clutch releases and it revolves freely on its shaft.
Once the stator becomes inactive, there is no further
multiplication of engine torque within the converter. At
this point, the converter is merely acting as a fluid
coupling as both the converter pump and turbine are
being driven at approximately the same speed - or at a
one-to-one ratio.
A hydraulic system pressurized by a gear type pump
provides the working pressure required to operate the
friction elements and automatic controls.
External control connections to transmission are:
Manual Linkage
Engine Vacuum
12 Volt Electrical
Signal
To select the desired op-
erating range.
To operate a vacuum mod-
ulator unit.
To operate an electrical
detent solenoid.
A vacuum modulator is used to automatically sense
any change in the torque input to the transmission. The
vacuum, modulator transmits this signal to the pressure
regulator for line pressure control, to the 1-2 accumula-
tor valve, and to the shift valves so that all torque re-
quirements of the transmission are met and smooth
shifts are obtained at all throttle openings.
The detent solenoid is activated by an alectric switch
on the carburetor. When the throttle is fully opened, the
switch on the carburetor is closed, activating the detent
solenoid and. causing the transmission to downshift at
speeds below approximately 70 MPH.
The selector quadrant has six selector positions: P,R,
N,D,
L2,L1.
P.
*
- Park position positively locks the output shaft to
the transmission case by means of a locking pawl
to prevent the vehicle from rolling in either di-
rection. The engine may be started in Park
position.
R. - Reverse enables the vehicle to be operated in a
reverse direction.
N.
- Neutral position enables the engine to be started
and run without driving the vehicle.
D,
- Drive Range is used for all normal driving condi-
tions and maximum economy. Drive Range has
three gear ratios, from the starting ratio to
direct drive. Detent downshifts are available by
depressing the accelerator to the floor.
L2.
- L2 Range has the same starting ratio as Drive
Range, but prevents the transmission from shift-
ing above second speed to retain second speed
acceleration when extra performance is desired.
L2 Range can also be used for engine braking.
L2 Range can be selected at any vehicle speed,
and the transmission will shift to second gear and
remain in second until the vehicle speed or the
throttle are changed to obtain first gear operation
in the same manner as in D Range.
CHIVROLET CHASSIS SERVICE MANUAL
ELECTRICAL-BODY
AND
CHASSIS
12-56
DEPRESSED PARK 2-SPEED WIPER
AND
WASHER
CORVETTE
GENERAL DESCRIPTION
The 2-speed windshield wiper
(fig. 91)
consists
of a
compound wound
12
volt dc motor and
a
gear box section
containing
the
gear mechanism
and
relay control.
The
motor armature
is
fitted with
a
worm gear which drives
the main gear assembly and crank arm.
The relay control, consisting
of a
relay coil, relay
armature
and
switch assembly,
is
located in the gear
box"
section and controls the starting and stopping of the wiper
through
a
latching mechanism (fig. 92).
An electric .washer pump
is
mounted
on the
gear box
section
of the
wiper
and is
driven by the wiper unit gear
assembly (fig. 93).
SERVICE OPERATIONS
WIPER MOTOR
AND
WASHER
PUMP ASSEMBLY
REMOVAL AND INSTALLATION
1.
Raise vehicle hood
and
disconnect, ground lead
at
battery.
2.
Remove engine distributor shielding
and
left bank
spark plug wire vertical shield.
3.
Disconnect left bank spark plug wire bracket-to-
manifold and position assembly to one side.
4.
Disconnect ignition resistor at firewall, then remove
washer pump inlet
and
outlet hose
at
pump valve
assembly.
5.
Remove engine distributor
cap
and position
to one
side;
then disconnect washer pump
and
motor
as-
sembly lead wires.
6. Remove glove
box
door
and
compartment. Refer
to
Section
1
for
removal procedure.
7.
Make sure wiper arms
and
wiper motor are both
in
the parked position; then remove
the
wiper trans-
mission retaining clip and disconnect both transmis-
sion and spacer from crank arm (fig. 93).
8. Remove four wiper motor-to-dash wall mounting
bolts and remove wiper motor from vehicle.
9. With
the aid of
an assistant position the wiper motor
to
the
dash wall
and
install the four motor mounting
bolts,
making sure motor assembly
is in
parked
position.
GEAR
BOX
SECTION
—<
MOUNTING
^*^
GROMMET
MOTOR
_/
SECTION
MOUNTING
/"""GROMMET
ARMATURE
END
PLAY
ADJUSTING SCREW
AND LOCK
NUT
P
^
CRANK
^_ /GROMMETS
RELAY
Fig.
92 -
Relay Control
10.
Position left transmission assembly, spacer
and
right transmission assembly
on
crank arm, then in-
stall
the
retaining clip
in the
groove
in
the crank
arm.
11.
Install glove compartment and door assembly. Refer
to Section
1
for
installation procedure.
12.
Install washer pump and motor assembly lead wires;
then install engine-distributor cap.
13.
Install washer pump inlet
and
outlet hose
to
pump
valve assembly, then install ignition resistor
to
firewall.
14.
Connect left bank spark plug wire bracket-to-mani-
fold, vertical shield and engine distributor shielding.
ROTOR
CAM. ^
CAM SLOT-~-*"'-*
WASHER PUMP^.
DRIVE
PIN
m
M
VALVE
— ASSEMBLY
i
Fig.
91 - Wiper Assembly—Corvette
Fig.
93 - Washer Pump
CHEVROLET CHASSIS SERVICE MANUAL